Switch-contact for controllers and the like.



PATENTED JAN. 8, 1902 W s. D. BLACK. I SWITCH con-mow FOR CONTROLLERS AND THE LIKE,

APPLICATION FILED 00125. 1906.

UNITED STATES PATENT OFFICE. SAMUEL DUNCAN BLACK, or BALTIMORE, MARYLAND, AssIcNOR T0 MANUFACTURERS ENGINEERING COMPANY, OF BALTIMORE. MARY- LAND, A CORPORATION OF MARYLAND.

Specification of Letters Patent.

Patented Jan. 8. 1907.

Application filed 0ctober 25,1996. Serial No. 340.516.

To all whom it may concern:

Be it known that I, SAMUEL DUNCAN BLACK, a citizen of the United States, residing at Baltimore city, State -of Maryland, have invented certain new and useful Improvements in Switch-Contacts for Controllers and the Like, of which the following is a specification.

. 'lhis invention relates to improvement; in switch-contacts; and the principal object of the said invention is the improvement of controllers, rheostats, starting-bokes, and other apparatusto which the said invention may be applied by providing a switch-contact therefor which may be most easily and sexpeditiously re laced without in any way impairing the e ectrical efliciency of the contact.

It is well known that in controllers, rheostats, and other apparatus in which one or more contact wipers or brushes are made to pass over a series of contacts in making I means of screws. it frequently happens,

however, that these screws themselves become burned by the current, so that it becomes difiicult to remove them.

The present invention is designed to overcome the above difliculties by providing a switch-contact which may be replaced without the necessity of manipulating screws or the like by attaching the contact to the insulating-base orcther support by means of a socket-and-p-lug connection which is amply sufficient to retain the contact in position, but at the same time permits it to be readily removed and another ut in its place.

Several specific emliodiments of my said invention are illustrated in the accompanymg drawings, which form apart of this specification, and in which? Figure 1 represents a form of my invention, 1n elevation;

partly in section and part! Fig. 2, a cross-section taken t 'ough the plug and-socket members shown in Fig. l and looking to the right; Fi 3, a fragmentary sectional view of the soc et, showing a lug therein in elevation slightly different cm the plug shown in Fig. 1; Fig. 4, a view, part y in section and partly in elevation, showing my invention ap lied .to a contactsegment; Fig. 5, a front e ovation of the segment shown in Fig. 4; Fig. 6, a front elevation ofanother form of contact-segment to which my said invention may be applied; Fig. 7, a side elevation of the latter segment; Figs. 8, 9, and 10 re resent, partly-in section and partly in side e evation, three modifications of the form of my invention shown in Fig. 1; and Fi 11, a section taken on the line 11 11, Fi 9, looking to the left.

- In the lorm of the invention shown in Figs. 1 and 2 the socket member consists'of a preferably brass or other metal bolt 1, theper- .manent head of which consists of a flange 2 around the exterior of one end, while the other end has a screw-threaded extension 3 to receive a nut 4 A socket-chamber 5 extends longitudinally of the bolt for a suitable distance and opens at the flanged end thereof.

Adapted to fit snugly in the chamber 5, so

that it will be firmly held therein by the frictionof the same against the inner side walls bf the chamber, is a plug 6, of brass or other suitable conducting material, preferably split by longitudinal slots 7, as shown, and the sections slightly sprung apart, so that when forced in the socket the outward springing or expansion of the plug will more securely hold the same in the socket; Forming a head on one end of this plug is the contact button or block 8.

When applied to controllers, rheostats, and the like, the socket-bolt 1 passes through the insulating-plate P9 of the controller. By

means of the nut 4, with which is preferably used a we her 1,0, the head 2' of the socket can be drawn tightly against the plate 9, and the socket thus firmly secured in osition. The nut and washerare also prefera ly used for making the terminal electrical connection.

In order to prevent any liability of the portions 2 and 8 to become fused together by arcing around the side of the contact-button, the latter may be made to project over the flange, as shown'in Fig. 3. The danger of such fusing, however, is very remote.

In Figs. 4 and '5 I have shown a form of my invention in which a metal segment 1 1 is used for the contact instead of the button or block 8, in which case the plug members 6 or attached to the said segment. These plugs fit in socket members 1, which may be the same as the one shown in Fig. 1, or the sockets may be of the kind shown in Figs. 6 and 7, hereinafter described, or any other suitable form. The segment itself may be of any other desired form-such, for example, as the segment 12. (Shown in Figs. 6 and 7.)

Instead of having a screw-threaded extension 5 on the end of the socket member to engagea nut as shown in Fig. 1, for example-'- .one end of the socket member may be tapped out, as at 13, Fig. 8, 14 inserted therein. This construction is of course not limited to the specific form of the device shown, being applicable as well to any of the modifications hereinafter described and others. Also instead of splitting the plug the plug may be solid and the socket splitfor example, as shown in Fig. 9. In this case the bolt is provided with an elongated head 15, in which is formed a socketchamber 16, the side walls of said'head being split by the longitudinal slots 17. The shank 18 of the bolt is screw-threaded, as at 19, to receive a nut 20 for attaching the bolt to the controller-plate. In this case the head of the bolt sits in a recess 21 in the controller-plate and the shank of the bolt passes through a smaller opening 22. This smaller opening 22 forms, with the recess 21, a shoulder 23, against which the head of the bolt rests. The switch-contact in this case may be in the form of button 8 or any other suitable form, while the plug 24 is made solid, as shown.

Another form of my invention is shown in Fig. 10, wherein the plug member is the one which is permanently secured to the insulating plate and the socket member the one which is permanently secured to the switch contact or block. This is a mere reversal of the arrangement shown in Fig. 9. In Fig. 10 the lug member consists of the bolts 25, on the lead 26 of which is formed a preferably split plug 27, the said bolt being held in the insulating-plate 9 by a nut and washer, substantially as shown in Fig. 9. In case the form shown in Fig. 10. is used the insulatingplate 9 is rovided with openings 21 and 22, substantially as in the case illustrated in he socket member in the arrangement shown in F'g. 10 may consist of a sleeve 28,

the case of and an attaching-screw substituted.

in which is formed a socket-chamber 29 to fit the plug 27, the switch-contact 8. bein formed on or attached to one end. of said sleeve. This switch-contact mayobviously be of any I of the kinds hereinbefore referred to. More- I over, the socket-sleeve 28 may be split, as in the socket 15, Fig. 9, andthe plug 27 may be solid, as in the case of plug 24.

The above are only some of the many specific forms which my invention may assume, [and I do not desire to be understood as limiting the same to any one of them.

It will be evident from the constructions herein shown and described that when one of the contacts or blocks becomes damaged the same may be readily removed simply by with- 5 drawing the plug from the socket, or vice versa, when a fresh or new contact may be Having described my invention, what I claim is- 1. The combination with i of a plugmember to fit said socket, and a l switch-block consisting of a head on one of said members.

2. The combination with a socket, of means to secure said socket to a support, a plug adapted to fit said socket, and a switchblock on one end of said plu 3. The combination with a socket bolt I having a chamber opening through the head thereof, of a plug adapted to fit said c'ham bler, and a switch-block on one end of said 11g. p 4i The combination with a socket-bolt having a chamber opening through the head thereof, of a split plug adapted to fit said chamber, a switch-block on one end of said plug, and a nut for said bolt.

5. The combination with a switch-contact segment, of one or more plugs fast to saidsega socket member,

. ment, a socket member tofit eachof said plugs, and means to make the said sockets I fast to a support. 6. The combination with an insulating switch-plate for controllers and the like, of a socket member, socket member,

secure one of said switch-plate.

In testimony whereof 'I affix my signature in presence of two witnesses. I SAMUEL DUNCAN BLACK. Witnesses:-

ROBERT R. BARR, Gnonen F. HOFFMAN.

a plug member to fit said a switch-block forming a I, head on one of said members, and means to" members rigidly to said 

